FIGURE 1.11. Imaging the in vivo regulation of receptor input to the olfactory bulb by GABAB-mediated presynaptic inhibition.

FIGURE 1.11

Imaging the in vivo regulation of receptor input to the olfactory bulb by GABAB-mediated presynaptic inhibition. (A) Pseudocolor maps of the spH signal evoked by the odorant butyl acetate. The GABAB receptor agonist baclofen reduces the amplitude of the odorant-evoked response (middle panel) compared to control levels (left panel). The reduction was reversed by coapplication with the GABAB receptor antagonist CGP35348 (1 mM; right panel). All maps scaled to the maximum of the control response. (B) Maps of the spH signal evoked by methyl valerate before (left) and after (right) application of CGP35348. Maps are scaled to the maximum of the control response. While CGP increased the amplitude of the odorant-evoked responses, the set of responsive glomeruli did not change. Traces (right) show the effect of CGP35348 on the odorant-evoked spH signal in one glomerulus. (C) Pseudocolor map of the spH signal evoked by butyl acetate (BA) or methyl valerate (MV), overlaid on an image of the resting fluorescence of the dorsal olfactory bulb (different preparation from above). Each map is normalized to its own maximum. The region in the dashed box is enlarged in the insets (right). (From McGann, J.P. et al. Neuron, 48: 1039–1053, 2005.) (D) Traces showing the spH signal evoked in glomeruli A (top) and B (bottom) by each odorant. Each glomerulus is selectively activated by one of the two odorants. For each glomerulus, the response to the binary mixture is no different from its response to the single component presented alone. (From McGann, J.P. et al. Neuron, 48: 1039–1053, 2005.)

From: Chapter 1, Optical Imaging of Brain Activity In Vivo Using Genetically Encoded Probes

Cover of In Vivo Optical Imaging of Brain Function
In Vivo Optical Imaging of Brain Function. 2nd edition.
Frostig RD, editor.
Boca Raton (FL): CRC Press/Taylor & Francis; 2009.
Copyright © 2009, Taylor & Francis Group, LLC.

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